Right?  We've seen him as The Masked Marvel, the WW 1 Flying Ace, Joe Cool, various sports heroes including a 
very volatile tennis player, and a vulture among others.  Never once did I see a series of strips where he owned a modest Ice Cream truck business.  Monty from Robotman and Monty, sure.  Just never Snoopy.  He's more of a patron of the Ice Cream Truck type.
 
Though I haven't read every strip obviously.  I just don't think Schulz would have given him something 
that mundane.
 
Here's a short snippet of an episode of Transformers.  When I first watched the entire episode I fell off the chair laughing at this.  So even in context it's kinda weird.
 
 
Seems like something the Simpsons would do in a Transformers parody.  But it's 
totally in the series.